A second Texas healthcare worker has tested positive for Ebola after treating the first person diagnosed with the disease on U.S. soil. The unnamed worker follows the positive diagnosis of nurse Nina Pham, who is said to be in good condition. Both treated Thomas Eric Duncan, who died last week. The Centers for Disease Control has identified what it calls a “large group” of other workers involved in Duncan’s care who may be at risk. The nation’s largest nurses union, National Nurses United, has accused hospitals of failing to protect workers from the virus. On Tuesday, the CDC acknowledged it should have acted faster to respond to the Duncan case, saying it might have prevented the workers’ infections. CDC Director Thomas Frieden also announced the establishment of new units to respond to Ebola cases.

Dr. Thomas Frieden: “The second thing that we will be doing, starting today, is establishing a CDC Ebola response team. For any hospital anywhere in the country that has a confirmed case of Ebola, we will put a team on the ground, within hours, with some of the world’s leading experts in how to take care of and protect healthcare workers from Ebola infection.”